Remove "icheck build" test.

Does not build, is not being maintained, purpose is unclear.

Change-Id: I00f3bbc9580b57e3945882a411af502a78f4864f
Reviewed-by: Eike Ziller <eike.ziller@nokia.com>

src/libs/3rdparty/cplusplus/Symbols.h

@@ -341,10 +341,6 @@ public:
     bool isPureVirtual() const;
     void setPureVirtual(bool isPureVirtual);
 
-#ifdef ICHECK_BUILD
-    bool isEqualTo(const Function* fct, bool ignoreName = false) const;
-#endif
-
     // Symbol's interface
     virtual FullySpecifiedType type() const;